In “Gangster Squad,” a driven cop (Josh Brolin) has to go to great lengths to assemble an off-the-books team of lawmen to help him attempt to break the stranglehold flamboyant mobster Mickey Cohen (Sean Penn) had on the city of Los Angeles in the 1940s.

Josh Brolin's "Gangster Squad" Brawl With Sean Penn

Josh Brolin chats at the "Gangster Squad" premiere in Hollywood about his on-screen brawl with Sean Penn. How intense was it? And, who got more banged up? Plus, how many cars did they wreck for the movie? (Published Wednesday, Jan. 9, 2013)

Coming off helming the critically hailed action/comedy “Zombieland” and its follow-up “Thirty Minutes Or Less,” Fleischer was already topping many actors must-work-with lists, and adding in an action-packed tale inspired by real events and set in the glamorous environs of Old Hollywood proved irresistible to the actors, and director. “Every single time I want to do something new and fresh and different,” Fleischer tells NBC. “I never want to repeat myself, and this was an incredible opportunity getting to live in the 1940s for a little bit.”

The film offered specific personal lures for Brolin: “First, I’m proud of L.A.,” he explains. “I’ve really tried to embrace California as a lot. I remember being an actor studying in New York, everybody was kind of ashamed to be from California, especially from L.A. I really made a point about turning that around because California is pretty frickin’ great! So it’s a movie about California, about Los Angeles, and I love the idea of that first and foremost.”

“Secondly, Sean and I were looking to do another movie together,” Brolin added. “We’ve been friends for a long time, we had a great time working together on ‘Milk,’ so we were looking for something else.”

Previous working relationships also brought Stone, who appeared in Fleischer’s “Zombieland” and also co-starred with Golsing in “Crazy Stupid Love,” into the fold. “I really liked the script and the character, but I think what drew me the most was working with Ruben again, and with Ryan again.” Of re-teaming with Gosling as her mob moll’s love interest, she said: “It's nice because between takes we really get along – but when we're trying to take each other seriously it's pretty difficult. So it was good and bad!”

Gosling had other motivations as well. “I was a huge 'Dick Tracy' fan when I was a kid,” he said, “and when I read this I thought it wasn't quite as cartoonish but it had comic book sensibilities, and it just sort of resonated for me on that level.”

“I'd been looking for something to do again with Ryan, and with Ruben, because I was a huge fan,” said Mackie, who appeared with Gosling in “Half Nelson” and plays the Gangster Squad’s sole black member. “I was excited about it. I like the idea of race relations and where they were in the 1940s, the 1950s, the way that people reacted to each other postwar, post-economic struggles. It was an interesting time to be in the country and to be evolving as Americans.”

Patrick says “I've lost track” of the amount of cops, federal agents and other law enforcement officers he’s played in his career. “I’ve worn a lot of uniforms, but this is the first cowboy cop that I've ever played,” says the actor, who was drawn to his role as an aging crack shot lawman “because it wasn't just a cop: It was a guy with a Western heritage, and Ruben let me go crazy with the cowboy kind of part of it. He had me watching nothing but Westerns to prepare for this, so I had a great time doing that.”

Patrick says the story’s connection to real L.A. history was also part of the intrigue. “I was born about eleven years after this movie took place, in the '50s, and my mom and dad lived through this era,” he recalls. “It was a great time to be an American, I think. We had won World War II and the future was wide open. I think that we knew as a country there wasn't anything that we couldn’t tackle. And so it created a certain attitude. We'd really united with the war bonds and all that, and we really came together. It's a great generation of people and it's a no bulls**t kind of an attitude.”

“Sometimes fact is more interesting than fiction,” explains executive producer Dan Lin. “Mickey Cohen really was this over-the-top gangster who was both violent and could be really funny, and these squad members really did come together to save the city that we love, L.A.”